Blow-ope valve



Dec. 26, 1922. 1,439,720

' D. R. YARNALL.

BLOW OFF VALVE FILED sa -r. I8, 1919.

Patented 26, 1922.

UNITED STATEZii PATENT ()l l lCE.

DAVID ROBERT YARNALL, O1 PHILADELPHIA, PENNSYLVANIA, .ASSIGNOR TO YARNALL-VJARING- COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CO1? PORATION OF PENNSYLVANIA.

BLOW-OFF VALVE.

Application filed September 18, 1919,

To all whom it may (ZOIIUGT/t.

Be it known that T, Davin ltonnnfr Yan- NALL. a citizen oi: the United States, resid- .ing; at 316 Preston Street, Philadelphia, in the county of Philadelphia and State oi Pennsylvania, have invented a certain new and useful Blow-Off Valve of which the following is a specification.

My invention relates to blow-oil valves,

such as are used in steam boiler systems.

The purpose of my invention to provide a quick-acting reliable blow-oft valve which shall at the same time be 01": short face-- to-face length in the direction oi steam passage.

A further purpose is to supplement the holding power of a valve face held by pres sure against a seat by a spring-pressed movable seat on the opposite side.

A furtherpurpose is to provide a supple mental valve having two e'tl'ective seats and capable of quick operation in tandem with. a second blowofl valve having sure holding qualities.

Further purpose will appear in the specification and in the claims.

I have preferred to illustrate my invention by but one form each of swing-gate valve and slide gate valveamongthe'iorms in. which my invention might appear, selecting them as practical, eflicient, simple and inexpensive and at the same time well illus trating the principles of my inventon.

Figure l is a longitudinal section through the center of the valve.

Figure 2 is a side elevation of the disk and of the arm by which it is swung.

Figure 3 is a broken longitudinal section showing a slight modification.

Figures 4; and 5 are a transverse section upon line 4.l or Figure 5 and a side elevation, respectively, of a second form f the invention.

In the drawings similar numerals indicate like parts.

Many power plants place their blow-nit valves in pairs, arrangeiil in tanden. This is required by law in someStates. In such a case, it is necessary that one of the l3l0W0fi valves shall absolutely seal, Without regard to its speed of operation. The best valves for this purpose are of the plunger type and are relatively slow in operation. Under these circumstances it is desirable that the Serial No. 824,618.

other shall be quick-acting. The tightness of seal of this quick-acting valve is not of the same importance as its speed because of the presence of the plunger valve. v

Though the valve herein has other valuable uses it is intended prii 'ily for use as the quick-operating blow-oil valve oi. such a pair. It affords a tight seal and has a desirably short face-to-face length in tie direction oi. steam travel.

The valve casing is split transversely into two parts for convenience of access, the being shown at 6 and 7. These are bolted together, as at S, and are packed at 9.

They may be secured to the adjoining piping; in any desired way, and. I have illustrated a flange 10 at one side and a threaded opening ill. at the opposite side. In the form shown. in l? i 'ure 1 the steam preferably passes thron in the d' ction oi? the arrow.

The body the valve is ifH'OVlL-fitl with a main opening through oppositelr-tacimr fined seats 13 and it. against one which the valve disk 15 is adapted to be pressed in the closed position oi. the valve by reason oi the pressure of the steam. The seat against which the disk is pressed is determined by the direction oi? steam passage through the valve. l Vith that indicated by the arrow it would be se 14.

However, it is my intention to seal the disk against a seat on each side. eiiectivelv sealing on both sides. This not only adds to the tightness oi? the seal generallv. but in large measure relieves the space 12 of pressure. For this purpose. I provide a movable seat in the form of a sealing bushmg or sleeve 16. Its interior diameter is that of the aperture 17 in the disk. which also has a recessed. face 18. i

The bushing is pressed against the disk bv a spring 19. engages the opposite side 20 of the disk from the side 21 which seals against the seat 14. The bushing is provided with annular packing as and rests against a stop 24;. This may be adjustable and removable and threaded into the valve, where it is desired to make the spring tension adjustable or to provide for removal of the parts from the flanged side in Figure 1; or it may rest against a fixed stop 24, as in Figure 3, if these parts are not to be removable and adjustable in this way.

It will be evident that the sleeve or bushing 16 will grind against the disk 15, in operation, and by the wear will maintain tight surface contact.

The disk 15 may be made sepa ate from its arm 25, where this is desired and I have shown this construction in Figures 1 and 2, where the arm is inserted within an. opening 26 and is held in longitudinal position with respect to the disk by a cotter pin 27.

The arm 25 is apertured at 28 for the non circular end 29 of a shaft 30 by which the arm is swung. The shaft 30 is flanged at 31 to rest against packing 32 within a recess 33 and the flange is pressed against the packing by'a springfit which rests against the side of the recess 12 and presses against the end 29. The shaft 80 turns within an opening 85 in the part 7 of the valve casing. It is operated by an arm 36.

In Figure 3 the seats 13 and 1.3 on opposite sides of the space 12 are alike and each surrounds a movable seat 16 (and 16) of the character seen at the left in this figure, givinga combination. of a fixed and movable seat on the side toward which the steam is flowing and a movable seat effective upon the opposite side.

In the form shown in I igures 4t and 5, the valve is also made in two parts, 6 and 7, but both of these parts are flanged for attachment to the adjoining pipe sections. However, the valve disk 15 here is given, a straight line sliding movement, guided by the contour 37 of its space 12. It is moved by a thread 38 upon a shaft 39, turned by the ordinary valve wheel 10.

Whether the form be that of a swing gate valve, as in Figures 1-3, or a slide gate valve, as in Figures 4- a'nd 5, the construction oii'ers the same opportunities fordiiferences in many details, besides those noted,

in applying the principles of my invention and my second illustration is for the pur pose, largely, of indicating that my invention is advantageous with both forms.

Having thus described my invention, what I claim as new and desire to secure by Letters-Patent is:

1. In a blow-off valve, a valve body having a steam passage through it, oppositely spring-pressed movable valve seats surrounding the passage, circumferential packing for the seats, a valvemovable across the passage and means formoving the valve.

2.,In a blow-oft valve, a valve body having a steam passage through it, oppositely spring-pressed, movable valve seats surrounding the passage, circumferential packing for the seats, a valve movable across the passage, a fixed valve seat surrounding one of the movable seats and means for moving the valve.

8. Ina blow-off valve, a valve body having a steam passage through it, oppositely spring-pressed, movable valve seats -sur rounding the passage, circumferential packing for the seats, a valve movable across the passage,afixed valve seat surrounding each ofthe movable seats and means for moving the valve.

41. In a bloweofi'valve, a valve body having an opening through it.for steam passage. and oppositelyiacing fixed valve seats surrounding the opening, a valve movable betweenthe two. seats, axially movable valve seats coaxial with the fixed seats and on opposite sides of the valve, circumferential packing about the movable seats and spring means for holding one of saidmov'able seats against the valve face at the same time that fixed valve, seat u on the .sameside.

DAVID" OBERT YARNALL.

' the valve is pressed by the steam against the 

